[IPoIB] Avoid the SM (2/4)

[IPoIB] Avoid the SM (2/4)

This patch adds a new IOCTL to IPoIB for converting a destination Ethernet MAC address to a path record.  The path records is created using information from the broadcast group and previous work completions.

The limitations of this patch is that the rate is that of the broadcast group, which in a mixed rate fabric (SDR/DDR/QDR) will result in suboptimal data transfer rates.

Signed-off-by: Fab Tillier <ftillier@microsoft.com>
git-svn-id: svn://openib.tc.cornell.edu/gen1@1611 ad392aa1-c5ef-ae45-8dd8-e69d62a5ef86